U.S. patent number 4,540,722 [Application Number 06/339,290] was granted by the patent office on 1985-09-10 for dentin and enamel adhesive.
This patent grant is currently assigned to Minnesota Mining and Manufacturing Company. Invention is credited to James E. Bunker.
United States Patent |
4,540,722 |
Bunker |
September 10, 1985 |
Dentin and enamel adhesive
Abstract
Dental liner and primer compositions having improved adhesion to
dentin and containing a metal dissolved in a polar organic solvent,
said metal being selected from Fe, Cu, Mn, Co, Sn, Cr, Ni, and
Zn.
Inventors: |
Bunker; James E. (White Bear
Lake, MN) |
Assignee: |
Minnesota Mining and Manufacturing
Company (St. Paul, MN)
|
Family
ID: |
23328331 |
Appl.
No.: |
06/339,290 |
Filed: |
January 15, 1982 |
Current U.S.
Class: |
523/109; 526/266;
526/277; 526/278; 433/199.1; 526/274 |
Current CPC
Class: |
A61K
6/40 (20200101); A61K 6/30 (20200101); C08L
33/08 (20130101); A61K 6/30 (20200101); C08L
33/10 (20130101); A61K 6/30 (20200101); C08L
33/068 (20130101); A61K 6/30 (20200101); C08L
33/14 (20130101); A61K 6/30 (20200101); C08L
33/08 (20130101); A61K 6/30 (20200101); C08L
33/10 (20130101); A61K 6/30 (20200101); C08L
33/068 (20130101); A61K 6/30 (20200101); C08L
33/14 (20130101) |
Current International
Class: |
A61C
13/02 (20060101); A61C 13/007 (20060101); A61K
6/02 (20060101); A61K 6/00 (20060101); C08F
30/00 (20060101); C08F 30/02 (20060101); C08F
130/00 (20060101); C08F 130/02 (20060101); C08K
3/00 (20060101); C08L 43/00 (20060101); C08K
3/10 (20060101); C08L 43/02 (20060101); C08F
130/02 () |
Field of
Search: |
;526/266,274,277,278
;523/109 |
References Cited
[Referenced By]
U.S. Patent Documents
|
|
|
2856390 |
October 1958 |
Coover et al. |
4182035 |
January 1980 |
Yamauchi et al. |
4222780 |
September 1980 |
Shibantani et al. |
4235633 |
November 1980 |
Tomioka et al. |
4251565 |
February 1981 |
Bowen |
4259075 |
March 1981 |
Yamauchi et al. |
4259117 |
March 1981 |
Yamauchi et al. |
|
Foreign Patent Documents
|
|
|
|
|
|
|
2711234 |
|
Sep 1977 |
|
DE |
|
2818068 |
|
Nov 1978 |
|
DE |
|
Other References
Jedrychowski, J. R., Caputo, A. A., and Prola, J., "Influence of a
Ferric Chloride Mordant Solution on Resin--Dentin Retention", J.
Dent. Res., 60, 2, 134-138 (1981). .
Hendrickson, et al., Organic Chemistry, Third Edition, pp. 796-799,
(McGraw Hill Co., 1970). .
Bowen, R. L., "Adhesive Bonding of Various Materials to Hard Tooth
Tissues. VII. Metal Salts as Mordants for Coupling Agents", Dental
Adhesive Materials, Proceedings from a Symposium held Nov. 8-9,
1973, Moskowitz, H. D., Ward, G. T. and Woolridge, E. D., Eds. pp.
205-221 (1974). .
Bowen, R. L., "Adhesive Bonding of Various Materials to Hard Tooth
Tissues. XIV. Enamel Mordant Selection Assisted by ESCA (XPS)", J.
Dent. Res., 57, 4, 551-556 (1978). .
Bowen, R. L., McClendon, L. T., and Gills, T. E., "Adhesive Bonding
of Various Materials to Hard Tooth Tissues. XV. Neutron Activation
Analysis of Dentin Sorption of Mordant Salts", J. Dent. Res., 57,
2, 255-260 (1978). .
Chem. Ab. No. 90:192576v for Japanese Laid-Open Application No.
78-138441. .
Chem. Ab. No. 90:210171r for Japanese Laid-Open Application No.
78-21438. .
Chem. Ab. No. 90:210175v for Japanese Laid-Open Application No.
78-28339. .
Chem. Ab. No. 90:110006x and Suggested Translation of Claims for
Japanese Laid-Open Application No. 78-113843. .
Chem. Ab. No. 90:110007y and 90:127574d for Japanese Laid-Open
Application No. 78-134037. .
Chem. Ab. No. 90:157097t for Japanese Laid-Open Application No.
78-144939. .
Chem. Ab. No. 88:7867p and Suggested Translation of Claims for
Japanese Laid-Open Application No. 77-113089. .
Suggested Translation of Claims for Japanese Laid-Open Application
No. 78-30193. .
Chem. Ab. No. 89:65283b for Japanese Laid-Open Application No.
78-39331..
|
Primary Examiner: Wong, Jr.; Harry
Attorney, Agent or Firm: Sell; Donald M. Smith; James A.
Cleveland; David R.
Claims
What is claimed is:
1. Dental bonding compositions comprising a mixture of:
(a) free-radically polymerizable phosphorus compound which, upon
polymerization thereof, adheres to dentin and enamel,
(b) an effective amount of an ion of a metal selected from the
group consisting of Fe, Cu, Mn, Co, Sn, Cr, Ni, and Zn, dissolved
in a polar organic solvent, said ion enhancing adhesion of said
mixture to dentin upon polymerization of said mixture,
(c) sulfur compound having sulfur in the .sup.+2 or .sup.+4
oxidation state, said sulfur compound acting as an activator for
polymerization of said mixture,
(d) tertiary amine,
(e) polymerization catalyst, and
(f) diluent.
2. Dental bonding compositions according to claim 1, wherein said
polymerizable phosphorus compound comprises an organic ester of one
or more acids of phosphorus, said ester has chlorine or bromine
bonded directly to phosphorus, and the organic radical of said
ester contains at least one free-radially polymerizable functional
group.
3. Dental bonding compositions according to claim 2, wherein said
organic radical is the residue remaining after removal of one or
more hydroxyl hydrogen atoms from BIS-GMA or from an isomer of
BIS-GMA.
4. Dental bonding compositions according to claim 3, wherein
phosphorus is doubly bonded to an oxygen atom and is bonded to at
least one chlorine atom, and the ratio of said phosphorus to the
total amount of said BIS-GMA or isomers thereof is between 0.025:1
and 1:1.
5. Dental bonding compositions according to claim 1, wherein said
polymerizable phosphorus compound has olefinic functionality and
contains at least one ##STR8## moiety.
6. Dental bonding compositions according to claim 1, wherein said
ion is selected from the group consisting of Fe.sup.+3, Cu.sup.+2,
Mn.sup.+2, and Co.sup.+2.
7. Dental bonding compositions according to claim 1, wherein said
ion comprises Fe.sup.+3 ion.
8. Dental bonding compositions according to claim 6, wherein the
concentration of said ion of a metal in said dental bonding
composition is between about 5.2.times.10.sup.-5 and
1.9.times.10.sup.-2 weight percent based upon a comparison of the
equivalent weight of elemental metal to the weight of said
polymerizable phosphorus compound.
9. Dental bonding compositions according to claim 6, wherein said
ion comprises Fe.sup.+3 ion and the concentration of said Fe.sup.+3
ion in said polar organic solvent is between about
3.2.times.10.sup.-4 and 1.2.times.10.sup.-1 grams of iron per liter
of solvent, based upon an equivalent weight of elemental iron.
10. Dental bonding compositions according to claim 9, wherein said
polar organic solvent comprises ethanol and said concentration is
between about 3.2.times.10.sup.-3 and 3.2.times.10.sup.-2 grams of
iron per liter of solvent.
11. Dental bonding compositions according to claim 1, wherein said
sulfur compound comprises a potassium or sodium bisulfite or
arylsulfinate salt.
12. Dental bonding compositions according to claim 1, wherein said
tertiary amine comprises N,N-dihydroxyethyl-p-toluidine.
13. Dental bonding compositions according to claim 1, wherein said
polymerization catalyst comprises benzoyl peroxide.
14. Dental bonding compositions according to claim 1, wherein said
diluent comprises triethyleneglycol dimethacrylate or
1,6-hexanediol dimethacrylate.
15. A method for improving the adhesion to dentin of a dental liner
or primer composition comprising free-radically polymerizable
phosphorus compounds, comprising the step of adding to said
composition, prior to application thereof to a tooth surface, an
effective amount of a metal compound dissolved in a polar organic
solvent, said metal being selected from the group consisting of Fe,
Cu, Mn, Co, Sn, Cr, Ni, and Zn.
16. A method according to claim 15, wherein said dissolved metal
comprises Fe.sup.+3.
17. A method according to claim 16, wherein said polymerizable
phosphorus compound comprises an organic ester of one or more acids
of phosphorus, said ester has chlorine or bromine bonded directly
to phosphorus, and the organic radical of said ester contains at
least one polymerizable functional group.
18. A method according to claim 16, wherein said polymerizable
phosphorus compound has olefinic functionality and contains at
least one ##STR9## moiety.
19. Dental bonding compositions comprising a mixture of:
(a) free-radically polymerizable phosphorus compound which, upon
polymerization thereof, adheres to dentin and enamel, said
polymerizable phosphorus compound comprising an organic ester of
one or more acids of phosphorus, said ester having chlorine or
bromine bonded directly to phosphorus, the organic radical of said
ester containing at least one free-radically polymerizable
functional group, said organic ester having the formula ##STR10##
wherein m is 1 to 3,
m' and m" are zero or 1 and are the same or different,
n is 1 to 4,
n' and n" are independently zero to 4 and are the same or
different, with the proviso that n' and n" are both not zero,
p, p' and p" are zero or 1 and are the same or different,
m+n+2p=3 or 5,
m'+m"+n'+2p'+3 or 5,
m'+m"+n"+2p"=3 or 5,
R.sup.1 is a monovalent olefinic organic radical which can be
straight chain, branched, or cyclic, can contain skeletal hereto
atoms, and can be unsubstituted or substituted with
non-interferring moieties,
R.sup.2 and R.sup.3 divalent olefinic organic radicals which can be
straight chain, branched, or cyclic, can contain skeletal hereto
atoms, can be unsubstituted or substituted with non-interfering
moieties, and are the same or different,
X is Cl, Br, or R.sup.4, where R.sup.4 is an aliphatic or
oxyaliphatic radical having 1 to 12 carbon atoms, and each X is the
same as or different from other X, with the proviso that at least
one X is Cl or Br,
(b) an effective amount of an ion of a metal selected from the
group consisting of Fe, Cu, Mn, Co, Sn, Cr, Ni, and Zn, dissolved
in a polar organic solvent, said ion enhancing adhesion of said
mixture to dentin upon polymerization of said mixture,
(c) sulfur compound having sulfur in the .sup.+2 or .sup.+4
oxidation state, said sulfur compound acting as an activator for
polymerization of said mixture,
(d) tertiary amine,
(e) polymerization catalyst, and
(f) diluent.
20. Dental bonding compositions comprising a mixture of:
(a) free-radically polymerizable phosphorus compound which, upon
polymerization thereof, adheres to dentin and enamel, said
polyermizable phosphorus compound comprising an organic ester of
one or more acids of phosphorus, said ester having chlorine or
bromine bonded directly to phosphorus, the organic radical of said
ester containing at least one free-radically polymerizable
functional group, said organic ester having the formula ##STR11##
(b) An effective amount of an ion of a metal selected from the
group consisting of Fe, Cu, Mn, Co, Sn, Cr, Ni, and Zn, dissolved
in a polar organic solvent, said ion enhancing adhesion of said
mixture to dentin upon polymerization of said mixture,
(c) sulfur compound having sulfur in the .sup.+2 or .sup.+4
oxidation state, said sulfur compound acting as an activator for
polymerization of said mixture,
(d) tertiary amine,
(e) polymerization catalyst, and
(f) diluent.
21. Dental bonding compositions according to claim 20, wherein said
ion comprises Fe.sup.+3 ion, said polar organic solvent comprises
ethanol, the concentration of said Fe.sup.+3 ion in said solvent is
between about 2 and 700 ppm, said sulfur compound comprises a
potassium or sodium bisulfite or arylsulfinate salt, and the
concentration of said sulfur compound is between about 0.5 and 10
weight percent based on the total weight of said composition.
22. Dental bonding compositions comprising a mixture of:
(a) free-radically polymerizable phosphorus compound which, upon
polymerization thereof, adheres to dentin and enamel, said
polymerizable phosphorus compound having olefinic functionality,
containing at least one ##STR12## moiety, and comprising
glycerophosphate dimethacrylate, (b) An effective amount of an ion
of a metal selected from the group consisting of Fe, Cu, Mn, Co,
Sn, Cr, Ni, and Zn, dissolved in a polar organic solvent, said ion
enhancing adhesion of said mixture to dentin upon polymerization of
said mixture,
(c) sulfur compound having sulfur in the .sup.+2 or .sup.+4
oxidation state, said sulfur compound acting as an activator for
polymerization of said mixture,
(d) tertiary amine,
(e) polymerization catalyst, and
(f) diluent.
23. Dental bonding compositions comprising a mixture of:
(a) free-radically polymerizable phosphorus compound which, upon
polymerization thereof, adheres to dentin and enamel, said
polymerizable phosphorus compound having olefinic functionality,
containing at least one ##STR13## moiety, and comprising a compound
of the formula ##STR14## (b) An effective amount of an ion of a
metal selected from the group consisting of Fe, Cu, Mn, Co, Sn, Cr,
Ni, and Zn, dissolved in a polar organic solvent, said ion
enhancing adhesion of said mixture to dentin upon polymerization of
said mixture,
(c) sulfur compound having sulfur in the .sup.+2 or .sup.+4
oxidation state, said sulfur compound acting as an activator for
polymerization of said mixture,
(d) tertiary amine,
(e) polymerization catalyst, and
(f) diluent.
24. A method for improving the adhesion to dentin of a dental liner
or primer composition comprising a free-radically polymerizable
phosphorus compound of the formula ##STR15## comprising the step of
adding to said composition, prior to application thereof to a tooth
surface, an effective amount of a metal compound dissolved in a
polar organic solvent, said dissolved metal comprising Fe.sup.+3.
Description
TECHNICAL FIELD
This invention relates to the field of polymerizable compositions.
In addition, this invention relates to compositions for use as
liners to which are applied restoratives and composites useful for
the repair of teeth, and to compositions for use as primers to
which are applied adhesives useful in fastening orthodontic
brackets or crowns to teeth. This invention also relates to a
method for repairing, adhering, or altering the position of teeth,
through the use of such compositions as liners or primers.
BACKGROUND ART
Practitioners in the field of dentistry have long sought
polymerizable compositions which would adhere well to dentin (and
to tooth structure in general), and some commercially available
polymerizable compositions have been utilized as dentin
adhesives.
For example, there has been introduced in Japan a dental liner
composition, under the name "Clearfil Bond System F" (hereinafter,
"Clearfil"), utilizing a two-part resin system. The first
(catalyst) portion of such resin system contains a polymerizable
phosphoric acid of unreported structure, but believed to be
##STR1## and about 2 weight percent benzoyl peroxide. The second
(accelerator) part of such resin system contains an ethanolic
solution containing about 3 weight percent sodium benzene sulfinate
and about 1 weight percent N,N-dihydroxyethyl-p-toluidine (the
latter compound will be referred to hereafter as "DHPT").
My copending U.S. patent application Ser. No. 234,560, filed Feb.
13, 1981, now U.S. Pat. No. 4,482,505 describes polymerizable
compositions which adhere well to dentin and enamel. These
compositions contain an organic ester of one or more acids of
phosphorus, said ester having chlorine or bromine bonded directly
to phosphorus, and the organic radical of said ester containing at
least one polymerizable functional group.
R. L. Bowen has described another means for obtaining adhesion to
dentin, through the use of a multiple step procedure. In a first
step of such procedure, a "mordant" prewash solution containing a
cation having greater electronegativity than calcium (e.g.,
Fe.sup.+3, Cu.sup.+2, Al.sup.+3, Zn.sup.+2, or Co.sup.+2) is
applied to a treatment site of a tooth. In a second step, a
"polyfunctional surface-active comonomer", or "polySAC", is applied
to the prewash-treated tooth surface. Next, a dental resin or
composite material is applied to the polySAC-treated tooth surface
and allowed to harden, see U.S. Pat. No. 4,251,565, Bowen, R. L.,
"Adhesive Bonding of Various Materials to Hard Tooth Tissues. VII.
Metal Salts as Mordants for Coupling Agents", Dental Adhesive
Materials, Proceedings from a Symposium held Nov. 8-9, 1973,
Moskowitz, H. D., Ward, G. T., and Woolridge, E. D., Eds., pp.
205-221 (1974), Bowen, R. L., "Adhesive Bonding of Various
Materials to Hard Tooth Tissues. XIV. Enamel Mordant Selection
Assisted by ESCA (XPS)", J. Dent. Res., 57, 4, 551-556 (1978), and
Bowen, R. L., McClendon, L. T., and Gills, T. E., "Adhesive Bonding
of Various Materials to Hard Tooth Tissues. XV. Neutron Activation
Analysis of Dentin Sorption of Mordant Salts", J. Dent. Res., 57,
2, 255-260 (1978). Additional information concerning the effect of
mordant solutions (using ferric chloride as the mordant species) is
contained in Jedrychowski, J. R., Caputo, A. A. and Prola, J.,
"Influence of a Ferric Chloride Mordant Solution on Resin-dentin
Retention", J. Dent. Res., 60, 2, 134-138 (1981).
DISCLOSURE OF INVENTION
The above-described mordant prewash technique requires that the
dentist employ a separate prewash step prior to application of a
dental liner or primer composition to the treatment site. It would
be desirable to eliminate this prewash step. The present invention
provides, in one aspect, dental liner or primer compositions
(hereafter sometimes referred to collectively as "dental bonding
compositions") comprising a mixture of:
(a) polymerizable phosphorus compound,
(b) an effective amount of a metal selected from Fe, Cu, Mn, Co,
Sn, Cr, Ni, and Zn, dissolved in a polar organic solvent,
(c) sulfur compound having sulfur in the .sup.+2 or .sup.+4
oxidation state,
(d) tertiary amine,
(e) polymerization catalyst, and
(f) diluent.
The present invention also provides a method for improving the
adhesion to dentin of a dental liner or primer composition
comprising polymerizable phosphorus compounds, comprising the step
of adding to said composition, prior to application thereof to a
tooth surface, an effective amount of a metal dissolved in a polar
organic solvent, said metal being selected from Fe, Cu, Mn, Co, Sn,
Cr, Ni, and Zn.
Said dental bonding compositions are mixed together a short period
prior to use (e.g., within 24 hours prior to use) and can be
applied directly to dentin. A dental restorative, composite, or
adhesive composition is then applied to the dental bonding
composition-treated tooth surface, and, if desired, a dental device
(e.g., an orthodontic bracket or a crown) is applied thereto. The
dental restoration is completed by allowing the dental restorative,
composite, or adhesive composition to harden.
Through the use of said dental bonding compositions, use of a
mordant prewash step can be eliminated. Adhesion to dentin of
dental restorations prepared with said dental bonding compositions
is greater than adhesion to dentin of corresponding dental
restorations prepared using dental liners or primers which do not
contain said component (b) above.
DETAILED DESCRIPTION
Polymerizable Phosphorus Compound
In the practice of the present invention, the polymerizable
phosphorus compound (viz., component (a) above) is preferably an
organic ester of one or more acids of phosphorus (hereafter
referred to as "phosphorus acid esters"), said ester having
chlorine or bromine bonded directly to phosphorus, and the organic
radical of said ester containing at least one polymerizable
functional group. Said phosphorus acid esters can be characterized
by the formulas (I) and (II): ##STR2## wherein m is 1 to 3,
m' and m" are zero or 1 and are the same or different,
n is 1 to 4,
n' and n" are independently zero to 4 and are the same or
different, with the proviso that n' and n" are both not zero,
p, p', and p" are zero or 1 and are the same or different,
m+n+2p=3 or 5,
m'+m"+n'+2p'=3 or 5,
m'+m"+n"+2p"=3 or 5,
R.sup.1 is a monovalent olefinic organic radical (preferably
alkenyl, alkenoxy, cycloalkenyl, aralkenyl, or alkenaryl, having 2
to 40 carbon atoms) which can be straight chain, branched, or
cyclic, can contain skeletal hetero atoms, i.e., atoms other than
carbon (e.g., oxygen, sulfur, or non-basic nitrogen atoms), and can
be unsubstituted or substituted with non-interfering moieties,
e.g., moieties which do not interfere with free-radical
polymerization of said phosphorus acid esters,
R.sup.2 and R.sup.3 are divalent olefinic organic radicals
(preferably alkenylidene, oxyalkenylidene, cycloalkenylidene,
arylenealkenylidene, or alkenylidenearylene, having 2 to 40 carbon
atoms) which can be straight chain, branched, or cyclic, can
contain skeletal hetero atoms, can be unsubstituted or substituted
with non-interfering moieties, and are the same or different,
and
X is Cl, Br, or R.sup.4, where R.sup.4 is an aliphatic or
oxyaliphatic radical having 1 to 12 carbon atoms, and each X is the
same as or different from other X, with the proviso that at least
one X is Cl or Br.
Compounds of formula I and II contain trivalent or pentavalent
phosphorus atoms. In compounds of formula I, phosphorus is bonded
to at least one chlorine or bromine atom. In compounds of formula
II, at least one phosphorus atom is bonded to at least one chlorine
or bromine atom. Preferably phosphorus is bonded to chlorine. The
preferred phosphorus acid esters desirably contain at least one
double bond between phosphorus and oxygen or sulfur, with a double
bond to oxygen being preferred. Most preferably two or more
polymerizable functional groups per phosphorus atom are contained
in the preferred phosphorus acid esters. Also, the phosphorus acid
esters are preferably liquids at room temperature.
The polymerizable functional group in the preferred phosphorus acid
esters is a free-radically polymerizable group, such as an olefin,
and is most preferably a monofunctional or difunctional acryl or
methacryl radical. Other polymerizable functional groups include
monofunctional or difunctional vinyl, allyl, crotyl, and cinnamyl
radicals.
Representative preferred phosphorus acid esters include: ##STR3##
as well as mixtures of more than one of the above compounds.
The preferred phosphorus acid esters can be used individually or in
the form of adducts containing more than one phosphorus acid ester.
Preferably, the phosphorus acid esters are prepared by combining a
chlorine- or bromine-containing phosphorus acid (e.g., phosphorus
oxychloride, POCl.sub.3, also known as phosphoryl chloride) with a
polymerizable monomer having at least one reactive hydroxyl group
(e.g., BIS-GMA and isomers thereof, sometimes referred to
collectively hereafter as "BIS-GMA", such as those isomers obtained
by replacement of one or both of the 2-hydroxypropylene moieties of
BIS-GMA with 2-hydroxymethylethylene moieties). Such polymerizable
monomers having at least one reactive hydroxyl group will be
hereafter referred to as "hydroxylated monomers". When the
hydroxylated monomer has a high initial viscosity, it is preferable
to mix the phosphorus acid with the hydroxylated monomer and a
suitable diluent (which diluent is preferably said component (f),
above), e.g., triethyleneglycol dimethacrylate.
The phosphorus acid and hydroxylated monomer will react at low
temperature, e.g., at room temperature, and the reaction mixture
will increase in viscosity, preferably reaching an equilibrium
state that is stable over time. The reaction product of such a
mixture will generally be an adduct, the phosphorus acid esters of
which are the product of reactions between some or all of the
various hydroxyl groups of the hydroxylated monomer and available
chlorine or bromine atoms of the phosphorus acid. Sufficient
phosphorus acid should be added to the hydroxylated monomer to
provide good bonding and handling performance in liner and primer
compositions prepared therewith. For an adduct prepared by
combining phosphorus oxychloride and BIS-GMA, about 0.25 to twenty
percent by weight phosphorus oxychloride, and preferably about one
to ten percent by weight phosphorus oxychloride should be used,
based on the weight of BIS-GMA. Because BIS-GMA contains two
hydroxyl groups per molecule, the above weight percentage values
represent equivalent ratios of POCl.sub.3 to BIS-GMA of about
0.025:1 to 1:1, preferably about 0.05:1 to 0.5:1. Suitable
adjustment of such equivalent ratios should be made when the
phosphorus acid esters are prepared from hydroxylated monomers
having other hydroxyl functionality, e.g., monofunctionality or
trifunctionality. Also, suitable adjustment of such equivalent
ratios should be made when the phosphorus acid esters are prepared
from phosphorus acids other than phosphorus oxychloride. Expressed
in terms of the ratio of halogen atoms in the phosphorus acid to
hydroxyl groups in the hydroxylated monomer, the phosphorus acid
and hydroxylated monomer should be combined in a ratio of halogen
atom to hydroxyl group between about 0.0375:1 to 1.5:1, preferably
about 0.075:1 to 0.75:1.
If lesser amounts of phosphorus acid than those amounts sufficient
to provide good bonding and handling performance are used, the
resulting adduct may have low adhesion to dentin and enamel when
polymerized therewith. If larger amounts of phosphorus acid than
those sufficient to provide good bonding and handling are used, the
resulting adduct will tend to homopolymerize, thereby having
inadequate shelf life.
Other phosphorus acids which can be reacted with hydroxylated
monomers to prepare the preferred phosphorus acid esters used in
this invention include CH.sub.3 POCl.sub.2, PCl.sub.3, PCl.sub.5,
C.sub.6 H.sub.5 POCl.sub.2, C.sub.6 H.sub.5 OPOCl.sub.2, and
PBr.sub.3. Such phosphorus acids can be used singly or in
combination. Phosphorus oxychloride is a preferred phosphorus acid
for use in the preparation of the preferred phosphorus acid esters
used in this invention.
Other hydroxylated monomers which can be used to prepare the
preferred phosphorus acid esters used in this invention include
hydroxyethyl methacrylate, pentaerythritol triacrylate, glycerol
dimethacrylate, methyl vinyl alcohol, vinyl benzyl alcohol, allyl
alcohol, crotyl alcohol, and cinnamyl alcohol.
The mixing of phosphorus acid and hydroxylated monomer can be
carried out at room temperature. The attainment of equilibrium
between the phosphorus acid and hydroxylated monomer can be
determined by observing the viscosity of the adduct over time, with
equilibrium being indicated by a leveling off of such
viscosity.
Other polymerizable phosphorus compounds which can be used as said
component (a) include compounds containing olefinic functionality
and at least one ##STR4## moiety, such as glycerophosphate
dimethacrylate and the polymerizable phosphorus compounds described
in U.S. Pat. Nos. 4,182,035, 4,222,780, 4,235,633, and 4,259,075,
O.L.S. Nos. 2711234 and 2818068, and Japanese laid-open application
Nos. 77-113089, 78-30193, 78-39331, 78-67740, 78-69494, 78-110637,
78-113843, 78-134037, 78-144939, 78-138441, 79-21438, and 79-28339.
Of the polymerizable phosphorus compounds described therein, the
compound ##STR5## is a preferred polymerizable phosphorus compound
for use in the present invention.
Metal Solution
Said solution of a metal, hereafter sometimes referred to as the
"metal solution" (viz., component (b) above) enhances the adhesion
of the other components of the dental bonding composition to dentin
upon polymerization thereof. Metal solutions containing ions such
as Fe.sup.+3, Cu.sup.+2, Mn.sup.+2, and Co.sup.+2 ions are
preferred, and metal solutions containing Fe.sup.+3 ion are most
preferred. Metal solutions containing more than one metal (e.g.,
solutions containing Fe.sup.+3 ion and Mn.sup.+2 ion) can be used
if desired.
The metal solution can be prepared by dissolving a salt of the
desired metal in a suitable polar organic solvent. Suitable metal
salts include FeCl.sub.3, Fe(NO.sub.3).sub.3, CuCl.sub.2,
Cu(NO.sub.3).sub.2 CuSO.sub.4, MnCl.sub.2, MnF.sub.2, CoCl.sub.2,
SnCl.sub.4, CrCl.sub.3, NiCl.sub.2, ZnCl.sub.2, hydrates thereof,
and mixtures thereof. The polar organic solvent preferably is a
solvent for both the metal and for the polymerizable phosphorus
compound. Suitable polar organic solvents include alcohols (e.g.,
ethanol), ketones (e.g., acetone), polar heterocycles (e.g.,
tetrahydrofuran), said diluent (f), above (also described in
greater detail below), and mixtures thereof. Other substances which
are poor solvents for the polymerizable phosphorus compound (e.g.,
water) can be used as the polar organic solvent if desired, but
preferably such other substances are not used or are excluded.
Absolute ethanol is a preferred polar organic solvent. Other
adjuvants, such as buffering agents, fungicides, dyes, pigments,
indicators, and the like can also be added to the metal solution if
desired.
The concentration of metal in the metal solution should be
sufficient to provide an effective amount of metal in the dental
bonding composition. An "effective amount", as used herein, is an
amount sufficient to provide improved adhesion to dentin of dental
restorations prepared with the dental bonding compositions of the
invention, compared to dental restorations prepared with
corresponding dental bonding compositions which do not contain said
metals. An effective amount of metal in the dental bonding
composition is a non-toxic amount, preferably between about
5.2.times.10.sup.-5 and 1.9.times.10.sup.-2 weight percent of metal
based on the weight of said polymerizable phosphorus compound (a).
The "concentration of metal", as used herein, is based upon the
equivalent weight of elemental metal present, although, of course,
a substantial portion of the metal in the metal solution may be in
ionic form. The concentration of metal in the metal solution can
range between trace amounts and the limit of solubility (when mixed
with any other components of the metal solution) of the metal
cation. Preferably, the concentration of metal in the metal
solution is chosen such that mixing a given volume (e.g., one drop)
of the metal solution with an equal volume(s) of solution(s)
containing said components (a), (c), (d), (e), and (f) will provide
the desired concentration of metal in the resulting dental bonding
composition. For metal solutions containing Fe.sup.+3 ion in
ethanol, the preferred concentration of iron is between about
3.2.times.10.sup.-4 and 1.2.times.10.sup.-1 grams of iron per liter
of ethanol, and most preferably is between about
3.2.times.10.sup.-3 and 3.2.times.10.sup.-2 grams of iron per liter
of ethanol. Similar concentration ranges are preferred for other
metals and other solvents, and range between about 2 to 700 parts
per million by weight ("ppm") of metal in solvent, and most
preferably between about 20 to 200 ppm.
Sulfur Compound
Said sulfur compound having sulfur in the .sup.+2 or .sup.+4
oxidation state, hereafter sometimes referred to as the "sulfur
compound", (viz., component (c) above) acts as an activator for
polymerization of the dental bonding compositions of this
invention. "Oxidation state", as used herein, is defined according
to Hendrickson et al., Organic Chemistry, Third Edition, pps.
796-799 (McGraw Hill Co., 1970). Suitable sulfur compounds are
ordinarily alkali metal salts, such as potassium or sodium salts,
or ammonium salts, of sulfur-containing anions such as sulfinate or
sulfonate anions. Additional sulfur compounds which can be used in
this invention include the salts of sulfurous acid having the
following formulas (III), (IV), (V), and (VI): ##STR6## wherein M
is a metal from Group I of the Periodic Table of the Elements, or a
cation of the formula N(R.sup.5).sub.4.sup.+ where R.sup.5 is a
hydrogen atom, a monovalent alkyl or cycloalkyl radical having
about 1 to 8 carbon atoms, or two R.sup.5 taken together with the
nitrogen atom to which they are joined combine to form a 5 to 7
membered ring, each R.sup.5 is the same as or different from other
R.sup.5, and R.sup.5 can contain hetero atoms which do not
interfere with the functioning of the salt of sulfurous acid as an
aid to polymerization of the polymerizable liquid monomer, such as
oxygen, sulfur, or nitrogen. Such salts of sulfurous acid are
ordinarily alkali metal salts, such as potassium or sodium salts or
ammonium or alkylammonium salts, of bisulfite, metabisulfite,
hydrosulfite, or sulfite anions.
Suitable sulfur compounds include C.sub.6 H.sub.5 SO.sub.2 Na,
CH.sub.3 C.sub.6 H.sub.4 SO.sub.2 K, C.sub.6 H.sub.5 SO.sub.3 Na,
LiHSO.sub.3, NaHSO.sub.3, KHSO.sub.3, NH.sub.4 HSO.sub.3, Li.sub.2
S.sub.2 O.sub.5, K.sub.2 S.sub.2 O.sub.5, Na.sub.2 S.sub.2 O.sub.5,
(NH.sub.4).sub.2 S.sub.2 O.sub.5, Na.sub.2 S.sub.2 O.sub.4, K.sub.2
S.sub.2 O.sub.4, (NH.sub.4).sub.2 S.sub.2 O.sub.4, Li.sub.2
SO.sub.3, Na.sub.2 SO.sub.3, K.sub.2 SO.sub.3, (NH.sub.4).sub.2
SO.sub.3, and mixtures thereof. Sodium benzene sulfinate is a
preferred sulfur compound.
The amount of sulfur compound used is an amount sufficient to
provide good bonding and handling performance (e.g., good shelf
life and working time) in dental bonding compositions of the
invention prepared therewith. A preferred amount is between about
0.5 to 10 weight percent sulfur compound based on the total weight
of the dental bonding composition. The sulfur compound is
preferably dissolved in a suitable solvent, such as an alcohol
(e.g., ethanol), so that the desired amount of sulfur compound can
be readily combined with the other components of the dental bonding
composition.
Tertiary Amine
Said tertiary amine, (viz., component (d) above) acts as a
polymerization accelerator for the dental bonding compositions of
this invention.
Suitable tertiary amines include DHPT, N,N-dimethyl-para-toluidine,
N,N-bis(2-hydroxyethyl)-3,5-xylidine, and the like. DHPT is a
preferred tertiary amine.
The amount of tertiary amine used is an amount sufficient to
provide good bonding and handling performance in dental bonding
compositions of the invention prepared therewith. A preferred
amount is between about 0.1 to 10 weight percent tertiary amine on
the total weight of the dental bonding composition. The tertiary
amine is preferably dissolved in a suitable solvent, such as an
alcohol (e.g., ethanol), so that the desired amount of tertiary
amine can be readily combined with the other components of the
dental bonding composition.
Polymerization Catalyst
Said polymerization catalyst (viz., component (e) above) promotes
polymerization of the dental bonding compositions of this
invention.
Suitable polymerization catalysts include free-radical initiators
such as peroxides, e.g., benzoyl peroxide, acetyl peroxide, lauroyl
peroxide, and t-butyl hydroperoxide. Benzoyl peroxide is a
preferred free-radical initiator. Photoinitiators (i.e.,
light-activatable catalysts) such as monoketals of aromatic
1,2-diketones or a combination of benzil and a dialkylamino
acrylate or methacrylate can also be used. The amount of
polymerization catalyst is an amount sufficient to provide good
bonding and handling performance in dental bonding compositions of
the invention prepared therewith. A preferred amount is between
about 0.05 to 5 weight percent polymerization catalyst based on the
total weight of the dental bonding composition. The polymerization
catalyst preferably is dissolved in a suitable solvent (e.g., said
diluent (f), above), and preferably is combined with said
polymerizable phosphorus compound prior to shipment thereof to the
user.
Diluent
Said diluent (viz., said component (f), above) serves to reduce the
viscosity of the dental bonding compositions of the invention, and
thereby enhance the penetration thereof into the microstructure of
the tooth treatment site (e.g., into the dentin tubules). Also, the
diluent preferably copolymerizes with and increases the crosslink
density of the dental bonding composition, thereby increasing the
hardness and strength (e.g., diametral tensile strength)
thereof.
Suitable diluents include triethyleneglycol dimethacrylate
(hereafter referred to as "TEGDMA"), 1,4-butanediol dimethacrylate,
1,6-hexanediol dimethacrylate, 1,8-octanediol dimethacrylate,
trimethylolpropane trimethacrylate, tetraethyleneglycol
dimethacrylate, neopentylglycol dimethacrylate, hydroxyethyl
methacrylate, bisphenol A dimethacrylate, glycidyl methacrylate,
styrene, vinyl acetate, and mixtures thereof. Preferred diluents
have methacrylic functionality. TEGDMA and 1,6-hexanediol
dimethacrylate are most preferred diluents.
The amount of diluent should be sufficient to lower the viscosity
of the dental bonding composition to a level sufficient to provide
good bonding and handling performance (e.g., ease of mixing). If
the diluent is mixed with the polymerizable phosphorus compound
(without addition of other components of the dental bonding
composition), the viscosity of the resulting mixture preferably is
between about 5 and 5000 cps at 25.degree. C., and most preferably
is less than about 3500 cps at 25.degree. C., and the diluent
preferably is between about 25 to 75 percent by volume of said
mixture. Addition of solutions containing the remaining components
of the dental bonding composition will typically further reduce the
viscosity of the dental bonding composition below the preferred
upper limits for viscosity stated above.
Other Adjuvants
The dental bonding compositions of this invention can contain other
adjuvants such as surfactants, pigments, inhibitors, stabilizers
against oxidation, and the like. The amounts and types of such
adjuvants, and their manner of incorporation in the dental bonding
compositions of this invention, will be essentially the same as
currently used in existing dental liner and primer compositions
familiar to those skilled in the art.
Packaging of the Dental Bonding Composition
The dental bonding compositions of the invention are preferably put
up in multiple-part packages. Maximum shelf life is obtained if the
metal of the metal solution is kept separate from the polymerizable
phosphorus compound, the sulfur compound, and the tertiary amine
until the time of use, as the metal may have a tendency to form
insoluble complexes with the above-mentioned other components,
thereby diminishing the bonding performance of dental restorations
prefered therewith. Also, the polymerizable phosphorus compound and
the sulfur compound are preferably kept separate until the time of
use, as addition of the sulfur compound to the polymerizable
phosphorus compound can promote homopolymerization of the latter
upon standing. However, the use of multiple-part packaging for the
dental bonding compositions of the invention is not a drawback,
because the individual components can be readily dispensed and
mixed due to their low viscosity and the small quantity of dental
bonding composition typically required for a dental
restoration.
For example, polymerizable phosphorus compound, polymerization
catalyst, and diluent can be combined in a first part, a suitable
first solvent (e.g., aqueous ethanol), sulfur compound, and
tertiary amine can be combined in a second part, and a suitable
second solvent (e.g., aqueous ethanol) and soluble salt of the
desired metal (e.g., FeCl.sub.3 or hydrate thereof) can be combined
in a third part. While uncombined, the resulting three-part package
will remain in a stable, uncured state. When the three parts are
mixed together, e.g., by spatulation, stirring, or other means, the
resulting liner composition will be ready for use.
Also, a polymerizable phosphorus compound, polymerization catalyst,
and diluent can be combined in a first part, a suitable first
solvent (e.g., aqueous ethanol or water) and sulfur compound can be
combined in a second part, a suitable second solvent (e.g., aqueous
ethanol or water) and tertiary amine can be combined in a third
part, and a suitable third solvent (e.g., aqueous or absolute
ethanol) and soluble salt of the desired metal can be combined in a
fourth part, and the four parts later mixed together for use.
The amount of each ingredient in such multiple-part packages should
be adjusted to allow sufficient working time for the practitioner
to mix and apply the dental bonding composition as desired,
together with attainment of the desired physical properties in the
cured dental restoration.
If desired, other combinations of polymerizable phosphorus
compound, desired metal, sulfur compound, tertiary amine,
polymerization catalyst, diluent, and any other desired adjuvants
can also be employed in multiple-part packages of dental bonding
compositions of this invention. Preferably, a multiple-part dental
bonding composition package offers ease of mixing, good shelf life,
and desirable physical properties after cure.
In addition, where desired, one or more of said components (c)-(d)
can be omitted from the dental bonding composition, provided that
the omitted component(s) are present in an adjacent layer of
uncured dental restorative, composite, or adhesive and can migrate
into the dental bonding composition during polymerization thereof.
However, this packaging method may diminish clinical
reproducibility of bonding results obtained therewith.
Technique
The dental bonding compositions of the invention can be used to
line prepared dentin and enamel surfaces of a dental restoration.
The dental bonding compositions of the invention are applied in a
manner similar to that used for existing dental liner compositions.
However, cavity preparation is simplified. Excavation can be
limited to the removal of damaged or defective tooth structure.
Undercutting of the cavity is generally not required for retention
of the restorative in the cavity. If desired, acid etching of the
cavity can be omitted. This invention therefore shortens the time
required for completion of a dental restoration and reduces trauma
to healthy tooth structure. Following application of the dental
bonding composition, the thus-treated dentin and enamel surfaces of
the area to be restored can be covered with conventional
restorative or composite compositions, which are hardened and
finished using conventional techniques.
The dental bonding compositions of the invention can also be used
as primers for the fastening of dental devices (e.g., orthodontic
brackets and crowns) with dental adhesives. The dental bonding
compositions of the invention are applied in a manner similar to
that used for existing dental adhesive primers. However,
application technique can be simplified. Satisfactory results can
often be obtained in the absence of acid etching, thereby reducing
damage to tooth enamel. Where desired, e.g., to obtain very high
bonding strength when dental devices are bonded to tooth enamel,
acid etching of the exposed tooth enamel can be employed.
The following examples are offered to aid understanding of the
present invention and are not to be construed as limiting the scope
thereof.
EXAMPLE 1
Preparation of a Dental Liner Composition
10 g of phosphorus oxychloride was dissolved in a polymerizable
monomer mixture (identified hereafter as "Resin A") containing 96 g
BIS-GMA, 2.0 g of benzoyl peroxide, 96 g TEGDMA, 0.13 g of
butylated hydroxytoluene, 0.34 g phenyl salicylate, and 0.24 g
glycidyl methacrylate. The resulting mixture was allowed to stand
at room temperature for 5 days. This reaction product was labeled
as part "A" and was used as the first part of a three-part dental
bonding composition (hereafter sometimes referred to as the
"bonding agent").
A solution of 3 percent by weight sodium benzene sulfinate and 1
percent by weight DHPT in absolute ethanol was prepared. This
solution was labeled as part "B" and was used as the second part of
the bonding agent.
A solution containing 4.1.times.10.sup.-4 weight percent iron in
absolute ethanol was prepared using ferric chloride hexahydrate,
FeCl.sub.3.6H.sub.2 O. This solution was labeled as part "C" and
was used as the third part of the bonding agent.
Adhesion of the bonding agent to unetched dentin was evaluated
using the following procedure. Four bovine teeth of similar age and
appearance were partially embedded in circular acrylic disks. The
exposed portion of each tooth was ground flat and parallel to the
acrylic disk using 120 grit silicon carbide paper-backed abrasive
mounted on a lapidary wheel, in order to expose the tooth dentin.
During this and subsequent grinding and polishing steps, the teeth
were continuously rinsed with water. Further grinding and polishing
of the teeth was carried out by mounting 400 grit silicon carbide
paper-backed abrasive and 600 grit silicon carbide paper-backed
abrasive on the lapidary wheel.
The teeth were stored in distilled water, and dried with oil-free
compressed air immediately prior to use. One drop of each part of
the bonding agent was placed in a mixing tray. The drops were mixed
together by hand spatulation for about 5 seconds, and the resulting
mixture was then painted onto the polished tooth surface and blown
into a thin film with compressed oil-free air. A conventional
orthodontic bracket adhesive ("Concise 1960", commercially
available from 3M) was placed on the pad surface of an orthodontic
bracket (bracket no. 007 and pad no. 065, commercially available
from American Orthodontics, Inc.) and the adhesive-coated bracket
pad was then applied to the bonding agent-treated dentin surface.
The tooth and bracket were allowed to stand for about 10 minutes at
room temperature, then stored in distilled water at 37.degree. C.
for 24 hours.
Adhesion of the bonding agent to the polished, unetched bovine
dentin was evaluated by placing the tooth mounting disk in a holder
and clamping the holder in the jaws of an "Instron" apparatus with
the layer of bonding agent parallel to the direction of pull. A
loop of orthodontic wire (0.44 mm diameter) was placed around the
bracket. The ends of the orthodontic wire were clamped in the
pulling jaws of the Instron apparatus, thereby placing the bonding
agent bond in shear stress. At a crosshead speed of 5 mm/min, the
average measured shear strength of the bonding agent-dentin bond
was 49.3 kg/cm.sup.2.
Using the above technique, the bond strength on polished bovine
enamel was also evaluated, without use of acid etching. Bond
strength on unetched enamel was an average of 64.1 kg/cm.sup.2.
In a comparison run, parts A and B were combined in a two-part
liner composition without the use of part C. When the liner
composition was evaluated using the above-described procedure, the
average bond strength on unetched dentin was 38.6 kg/cm.sup.2 and
the average bond strength on unetched enamel was 63.3 kg/cm.sup.2.
This comparison run shows that use of the metal solution of Part C
improved adhesion to dentin by approximately 27 percent and
improved adhesion to enamel by approximately 1 percent.
In a further comparison run, an isotonic ferric chloride mordant
solution containing 1.41 percent by weight FeCl.sub.3.6H.sub.2 O
was prepared and applied to polished dentin using the procedure of
example 3 of U.S. Pat. No. 4,251,565, but using a 1 minute
application time (instead of the thirty second application time
shown therein) and with rinsing of the mordant solution from the
tooth (rather than removal by suction as shown therein). Next, the
above-described parts A and B (but not part C) were mixed to form a
two-part liner composition. When this composition was evaluated for
adhesion to dentin using the above-described technique, the average
bond strength on unetched dentin was 30.1 kg/cm.sup.2. This
comparison run shows that use of the "mordant" prewash technique of
U.S. Pat. No. 4,251,565 actually decreases adhesion to dentin when
used with the two-part liner composition containing the
above-described parts A and B.
In yet a further comparison run, the "mordant" prewash procedure of
the preceeding paragraph was repeated, but using a prewash solution
containing 20 parts per millon by weight FeCl.sub.3.6H.sub.2 O in
absolute ethanol in place of the isotonic 1.41 weight percent
FeCl.sub.3 solution used previously. The average bond strength on
unetched dentin was 39.8 kg/cm.sup.2. This further comparative
example shows that an improvement in adhesion to dentin could be
obtained with a prewash solution containing a very small amount of
FeCl.sub.3 (a much more dilute solution than that suggested in said
U.S. Pat. No. 4,251,565), but the improvement in adhesion to dentin
amounted to only about 0.5 percent.
EXAMPLES 2-27 AND COMPARATIVE EXAMPLES 1-3
The procedure of Example 1 was repeated, using other compositions
in place of the three-part dental bonding composition containing
parts A, B, and C of Example 1. Set out below in Table I are the
example No., composition of each part of the dental bonding
composition, and the adhesion to polished, unetched dentin and to
polished, unetched enamel obtained using the dental bonding
composition of each example. Also set out below are comparison
examples showing the effect of omission of the metals used in this
invention.
The notes following Table I show the composition of each part of
the dental bonding compositions referred to therein. The notation
"ppm" refers to parts per million on a weight basis.
TABLE I ______________________________________ Dental bonding
composition Bond strength Bond strength Ex. No. or Part Part Part
on dentin, on enamel, Comp. Ex. No. one two three kg/cm.sup.2
kg/cm.sup.2 ______________________________________ 2 A B C1 46.2 --
3 A B C2 44.1 -- 4 A B C3 41.4 -- 5 A B C4 30.9 -- 6 A B C5 39.1 --
7 A B C6 41.7 -- 8 A B C7 41.1 -- 9 A B C8 49.8 65.2 10 A B C9 24.6
-- 11 A B C10 39.8 56.0 12 A B C11 39.2 66.1 13 A B C12 47.1 66.1
14 A B1 C13 47.6 66.1 15 A B2 C13 45.4 48.2 16 A B3 C13 63.8 53.2
17 A B4 C13 40.5 39.8 18 A B5 C13 56.0 51.7 19 A B6 C13 65.5 34.2
20 A B7 C13 65.0 49.8 21 A B8 C13 58.2 -- 22 A B8 C14 57.7 -- 23 A1
B9 C 51.0 21.3 24 A1 B9 C5 15.1 -- 25 A1 B9 C6 26.9 -- 26 A1 B9 C7
57.6 -- 27 A1 B9 C8 25.9 -- Comp. Ex. 1 A B8 C15 42.0 47.3 Comp.
Ex. 2 A B10 -- 36.4 54.6 Comp. Ex. 3 A1 B9 -- 17.0 32.7
______________________________________ Notes: A is "Part A " of
Example 1. A1 is "Clearfil" catalyst resin, commercially available
from Kuraray Co., Ltd., and believed to contain ##STR7## and about
2 wt. % benzoyl peroxide. B is "Part B" of Example 1. B1 is 3 wt. %
sodium benzene sulfinate in absolute ethanol B2 is 5 wt. % sodium
bisulfite in water. B3 is B2 plus 0.1 wt. % "Triton X-100"
surfactant (commercially available from Rohm and Haas Co.). B4 is 5
wt. % ammonium bisulfite in water. B5 is B4 plus 0.1 wt. % "Triton
X-100". B6 is 5 wt. % sodium metabisulfite in water. B7 is B6 plus
0.1 wt. % "Triton X-100". B8 is 5 wt. % sodium bisulfite in 50%
aqueous ethanol. B9 is "Clearfil" universal liquid, commercially
available from Kuraray Co., Ltd., and believed to contain about 3
wt. % sodium benzene sulfinate and about 1 wt. % DHPT in ethanol.
B10 is B plus 0.1 wt. % "Triton X-100". C is "Part C" of Example 1.
C1 is 20 ppm CuCl.sub.2 in absolute ethanol. C2 is 20 ppm
SnCl.sub.4 in absolute ethanol. C3 is 20 ppm MnCl.sub.2 in absolute
ethanol. C4 is 1 ppm FeCl.sub.3 in absolute ethanol. C5 is 2 ppm
FeCl.sub.3 in absolute ethanol. C6 is 5 ppm FeCl.sub.3 in absolute
ethanol. C7 is 50 ppm FeCl.sub.3 in absolute ethanol. C8 is 200 ppm
FeCl.sub.3 in absolute ethanol. C9 is 1000 ppm FeCl.sub.3 in
absolute ethanol. C10 is 20 ppm FeCl.sub.3 in TEGDMA. C11 is 20 ppm
FeCl.sub.3 in a 50/50 (by volume) mixture of BIS-GMA and TEGDMA.
C12 is 200 ppm FeCl.sub.3 in a 50/50 (by volume) mixture of BIS-GMA
and TEGDMA. C13 is 20 ppm FeCl.sub.3 and 1.5 wt. % DHPT in absolute
ethanol. C14 is 200 ppm FeCl.sub.3 and 1.5 wt. % DHPT in abosolute
ethanol. C15 is 1.5 wt. % DHPT in absolute ethanol.
These examples show that use of the metal solutions in dental
bonding compositions of this invention provided increased adhesion
to dentin and, in some cases, increased adhesion to enamel as well.
These examples also show that the degree of improvement in adhesion
was dependent upon the concentration of the metal solution, with
adhesion values increasing, then decreasing, as the concentration
of the metal solution was increased above trace concentration
levels.
Various modifications and alterations of this invention will become
apparent to those skilled in the art without departing from the
scope and spirit of this invention, and it should be understood
that this invention is not limited to the illustrative embodiments
set forth herein.
* * * * *